This application claims priority to and benefit of Canadian Patent Application No. 2,398,015, filed on Aug. 14, 2002, currently pending. It is incorporated herein by reference.
This invention is in the field of conveyors and in particular such a conveyor for unloading granular material from a belly dump transport vehicle.
A common problem in material handling is that of unloading granular material from belly dump trailers, rail cars and like transport vehicles. Such vehicles have a discharge located at the bottom of the hoppered cargo container under the center of the vehicle.
Conventionally, such belly dump vehicles are driven over a pit that has a conveyor connected thereto for carrying the material away. Rather than construct a permanent pit, alternative equipment for unloading such belly dump vehicles has been developed. Examples are disclosed in U.S. Pat. No. 5,297,914 to Ash, and U.S. Pat. No. 5,435,689 to Stonehouse. With these apparatuses a belly dump trailer is driven over a ramp so that the center discharge is located above a conveyor.
Belly dump vehicles are also unloaded using a short transfer conveyor having an intake hopper and a discharge end. The transport conveyor must be maneuvered into an operating position wherein the hopper is located under the center discharge of the vehicle and the conveyor discharge is located above the intake of a primary conveyor. Considerable jockeying of the conveyor and the vehicle is sometimes required to attain a satisfactory operating position since the vehicle must be located at the proper distance laterally from the primary conveyor intake, and fore and aft with respect to that intake, to allow the fixed length transfer conveyor to be positioned.
Similarly xe2x80x9cswing awayxe2x80x9d conveyors are known where the discharge end of a short transport conveyor is pivotally attached to the intake end of a primary conveyor. The opposite end of the transport conveyor has an intake hopper and wheels fixed at the outside end of the hopper that are oriented to allow the intake end to pivot about the discharge end. The belly dump vehicle is driven along side and the intake hopper is swung under the center discharge. Again the belly dump vehicle must be located at the proper distance so that the intake hopper can be properly position under the central discharge.
In some situations the intake of a primary conveyor can be maneuvered into the operating position, however the angle of elevation of the primary conveyor required to reach the input doors of many storage bins is such that this is often not possible. In any event it is awkward to maneuver the primary conveyor, and the concept of the short transfer conveyor was developed to avoid the problems inherent in unloading from the central discharge directly into the primary conveyor.
U.S. Pat. No. 5,499,899 to Hibbs discloses a mobile belt conveyor having a horizontal intake section that can be extended under the central discharge of a rail car or the like. The horizontal intake section is oriented at an angle to the primary conveyor itself, and the belt travels around the primary conveyor and intake section with the intake section extending and retracting from the lower end of the primary conveyor.
Telescoping belt conveyors are also known, for example as disclosed in U.S. Pat. No. 6,360,876 to Nohl et al., U.S. Pat. No. 6,003,658 to Best et al., and U.S. Pat. No. 4,624,357 to Oury et al.
It is an object of the present invention to provide a conveyor for unloading belly dump vehicles. It is a further object of the present invention to provide such a conveyor that has a lower telescoping section with a hopper mounted on the end, and wheels oriented for transverse movement such that the hopper may be readily positioned under a belly dump discharge.
The present invention provides, in one aspect, a conveyor apparatus comprising an upper conveyor tube having an upper discharge end and an open lower intake end. A lower conveyor tube has an open upper discharge end telescopically engaged with the upper conveyor tube, and a lower intake end with an intake hopper mounted on the lower intake end. A telescope actuator is operative to selectively extend and retract the lower conveyor tube with respect to the upper conveyor tube. At least one wheel is attached to the upper conveyor tube and is operative to support the lower intake end of the upper conveyor tube and the lower conveyor tube. The at least one wheel is oriented for travel transverse to the upper and lower conveyor tubes, and an elevating actuator is operative to raise and lower the at least one wheel with respect to the upper conveyor tube. A conveyor belt has a top run that passes through the hopper, lower conveyor tube, and upper conveyor tube, and a bottom run that passes under the conveyor tubes. A belt drive is operative to move the top run of the conveyor belt up through the conveyor tubes to carry material from the intake hopper to the upper discharge end of the upper conveyor tube.
In a second aspect the invention provides a conveyor apparatus comprising a primary conveyor having a primary intake operative to receive material for conveyance up the primary conveyor. An upper conveyor tube has an upper discharge end and an open lower intake end, and the upper discharge end is operatively connected to the primary intake such that the upper conveyor tube can pivot with respect to the primary intake, and such that the upper discharge end is supported by the primary intake. A lower conveyor tube has an open upper discharge end telescopically engaged with the upper conveyor tube, and a lower intake end with an intake hopper mounted thereon. A telescope actuator is operative to selectively extend and retract the lower conveyor tube with respect to the upper conveyor tube. A plurality of wheels are attached to the upper conveyor tube and are operative to support the lower intake end of the upper conveyor tube and the lower conveyor tube. The wheels are oriented for travel transverse to the upper and lower conveyor tubes, and a wheel drive is operative to rotate at least one wheel selectively in both directions. An elevating actuator is operative to raise and lower the wheels with respect to the upper conveyor tube. A conveyor belt has a top run that passes through the hopper, lower conveyor tube, and upper conveyor tube, and a bottom run that passes under the conveyor tubes. A belt drive is operative to move the top run of the conveyor belt up through the conveyor tubes to carry material from the intake hopper to the upper discharge end of the upper conveyor tube and into the primary intake.
The apparatus is readily maneuvered to a position under the belly dump discharge. To situate the belly dump vehicle in a position adjacent the apparatus the apparatus is moved out of the way by telescoping or swinging on the wheels. Once the belly dump vehicle is approximately in position, the hopper can be moved transversely on the wheels and longitudinally with the telescope actuator. The belly dump vehicle must be located only within a substantial range of fore and aft and in and out positions, reducing the time and effort required to position the vehicle.
Conveniently at least one of the wheels is driven by a hydraulic motor or the like, such that effort is further reduced. The upper conveyor tube and wheels only pivot about the upper discharge end of the upper conveyor tube. The lower conveyor tube and hopper can be raised up and down by the elevating actuator so that the lower conveyor tube can telescope easily with no resistance from wheels or skids resting on the ground and moving over bumps, holes and the like.